Rescue work is on to remove the people who are trapped under the rubble.
Five people have been rescued from the debris, news agency ANI reported.
One body has been recovered so far, officials said, as the rescue operations carried out by the State Disaster Response Force are underway.
Four persons escaped, four are suspected trapped. One of them was rescued by our rescuers alive," Director General of Police, Fire and Emergency Services, M N Reddi said in a tweet.
Bengaluru Mayor G Padmavati visited the spot and said quality issues in the construction was the main reason for the mishap.
Stating that one entire floor was constructed in an unauthorised manner, she said "strict and merciless action will be taken against the owner, architect and Bruhat Bengaluru Mahanagara Palike officials involved".
The injured are being treated in hospital.
The incident occurred near HSR Layout Police Station which is a residential area in the tech city.